title: Ca-activated chloride current and Na-Ca exchange have different timecourses during sarcoplasmic reticulum Ca release in ferret ventricular myocytes.
abstract: The aim of this work was to measure membrane currents activated by Ca release from the cardiac sarcoplasmic reticulum (s.r.). Intracellular Ca concentration ([Ca2+]i) was measured using fluo-3 in patch clamped cells. Calcium release from the s.r. (whether occurring spontaneously or evoked by caffeine) produced changes of membrane current which could be separated into a Ca-activated Cl current which was inhibited by DIDS or Cl removal and a Na-Ca exchange current. Both these currents had different time courses from the measured [Ca2+]i. Furthermore the Ca-activated Cl current decayed more quickly than did Na-Ca exchange. Possible explanations for the different kinetics of these two Ca-sensitive currents are discussed.
authors.affiliation: Department of Veterinary Preclinical Sciences, The University of Liverpool, Brownlow Hill and Crown Street, Liverpool, L69 3BX, UK.
authors.forename: A W
authors.initials: AW
authors.lastname: Trafford
authors.forename: M E
authors.initials: ME
authors.lastname: Díaz
authors.forename: D A
authors.initials: DA
authors.lastname: Eisner
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D018118:Chloride Channels / Q000502:physiology*; D005289:Ferrets; D006352:Heart Ventricles / Q000166:cytology / Q000378:metabolism; D066298:In Vitro Techniques; D007700:Kinetics; D008564:Membrane Potentials / Q000502:physiology; D009206:Myocardium / Q000166:cytology / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D012519:Sarcoplasmic Reticulum / Q000378:metabolism* / Q000502:physiology; D012964:Sodium / Q000378:metabolism*; D019831:Sodium-Calcium Exchanger / Q000502:physiology*; D013997:Time Factors; D016276:Ventricular Function
chemical_list: D018118:Chloride Channels; D019831:Sodium-Calcium Exchanger; D012964:Sodium; D002118:Calcium